1. Technical Field
The invention relates to the field of ductwork or pipe interior cleaning systems and more particularly to a large scale type cleaning plug apparatus for cleaning the interior of large interior diameter ducts or pipes such as sewer lines for example.
2. Background Art
Cleaning plugs or kites are well known and have been used generally by cleaners of waste collection systems, air duct work, and the like for loosening solid materials, such as dirt, stone, mud and other debris, from the interior walls of pipes or ducts.
Kites and other types of cleaning plugs are well known in the pipe cleaning art. For example, U.S. Pat. Nos. 5,336,333; 5,341,539; 5,068,940; 1,035,994; 2,481,152; 2,508,659; 4,141,753; 5,364,473; and 6,508,261 teach various embodiments of cleaning plugs or kites for use in the cleaning of the interior of pipes.
A cleaning plug or kite may be placed in the interior either of a pipe, such as a sewer line, or a duct, such as an air handling or air conditioning system in a building. The fluid flowing in the pipe is blocked by the bag device thereby expanding the first end of the kite. Generally, the first end of the kite is sized such that when the kite is fully expanded the first end approximates the size or diameter of the interior of the pipe. The fluid flow is then either totally stopped or a pressurized stream may flow between the outer edge of the kite and the interior wall of the pipe. Alternatively, an opening may be formed in the apex of the kite or bag to permit fluid flow therethrough. Such flow through the formed opening would increase the pressure of the resulting stream exiting through the kite as a result of the fluid flowing through a reduced cross-sectional area. Finally, the pulling of the rigging securing the kite or cleaning plug against the fluid pressure in the pipe often creates pockets or folds in the outer edge of the first end of the kite. Pressurized fluid jets or streams then can escape between the folds and the pipe's interior wall.
The relatively high pressure water or fluid is used to flush or wash undesired solid debris downstream through the pipe system.
Check valves are also well known in the art pertaining to valve structures. A check valves is a valve that permits flow in one direction only, that is to prevent backflow. Check valves have been used in past wastewater systems, such as in sluice gates. Known types of check valves include dual plate hinged and also all-rubber construction that seals and closes. An exemplary offeror of metal-hinged check valves is Techno Corporation of Millbury, Mass. (www.technovalve.com). Other check valve offerors are available and can be found readily through searching for check valves on the Internet.
Such a known check valve has not been used in the field of cleaning plugs or kites prior to the teaching of U.S. Pat. No. 6,508,261, issued Jan. 21, 2003 to the present Applicant.
However, the prior cleaning plugs or kites work optimally when the entire interior of the pipe was flooded or filled with the liquid. This optimal situation is not always feasible defeating the effectiveness of the known cleaning plugs or kites. A commonly occurring situation in which the entire interior of a pipe is not filled with a liquid is with a large diameter sewer pipe of the type having an interior passageway large enough to fit a standing person. In such large scale sewer systems, the level or depth of fluid flowing in the passageway may be only a few inches or a fraction of the passageway's diameter.
While the above-cited references introduce and disclose a number of noteworthy advances and technological improvements within the art, none completely fulfills the specific objectives achieved by this invention.
While the above cited references introduce and disclose a number of noteworthy advances and technological improvements within the art, none completely fulfills the specific objectives achieved by this invention.